[Note] USB Device Enumeration Process

•<Power Stage>

•Device pull high to 3.3V

•D+ : Full Speed (High Speed)

•D- : Low Speed

•Get Port Status Command to hub

•Set Port Feature

•Reset Device (Pull D+,D- low for 10ms)

•Detect full/high speed use chirp J/K

•Chirp J : D+

•Chirp K : D-

•High speed device send Chirp J, Host respond chirp JK to notice device ok.

•<Default Stage>

–Get Port Status – to see if reset complete

–Get Descriptor (Device Type)

–Reset

•<Address Stage>

–Set Address

–Get Descriptor
(Device Type)